Trace levels of anesthetics released during operations are potetial health hazards for operating room personnel. The common anesthetic agents, halothane, enflurane, and nitrous oxide, can be metabolized in vivo or converted to more reactive compounds in vitro. Ultraviolet light irradiation is used in some operating rooms in the U.S. to decrease intraoperative infections. Ultraviolet light irradiation directly decomposes halothane, for example, to toxicants and other photochemical products. To investigate the potential role of photochemical reactions on the occupational hazards of inhalation of trace concentrations of these agents by operating room personnel, rats and mice will be expsed to known concentrations of halothane, enflurane, or nitrous oxide before and after irradiation will be measured by electron capture gas liquid chromatography and mass spectrometry. The nature of the decomposition product(s), the inhalation toxicity of the irradiated gases, and the role of cytochrome P450 in the metabolism and toxicity of these compounds will be determined. Conversion of nitrous oxide to nitrogen dioxide and other oxidess of nitrogen will be determined chemically. Finally, the concentration of the anesthetic agents and their potentuial toxic decomposition products will be measured in the operating room. These data will be used to assess the potential human hazards from long-term occupational exposure.